


chemical reaction

by belial



Series: pH indicators [4]
Category: CA:TWS - Fandom, Captain America, Captain America (Movies)
Genre: Alpha/Beta/Omega Dynamics, Fluff, M/M, Multi
Language: English
Status: Completed
Published: 2014-07-02
Updated: 2014-07-02
Packaged: 2018-02-07 03:49:10
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,323
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1884210
Author URL: https://archiveofourown.org/users/belial/pseuds/belial
Summary: <blockquote class="userstuff">
              <p>Brock’s turning the big four-oh. While he deals with the ups and downs of everyday life, there are semi-nefarious plots afoot to give him a surprise party.  You’d think spies would be better at keeping such an event a secret… but the resulting present might be the best he’s ever had.  One-shot.</p>
            </blockquote>





	chemical reaction

**Author's Note:**

  * For [bofurrific](https://archiveofourown.org/users/bofurrific/gifts).
  * Translation into Русский available: [Химическая реакция](https://archiveofourown.org/works/13066389) by [Saysly](https://archiveofourown.org/users/Saysly/pseuds/Saysly)



> Disclaimer: I do not own the fandom, characters, etc. I make no profit from this. 
> 
> Notes: A/B/O dynamics but NO consent issues. Tooth rotting fluff! Whew.

Brock’s reading a curriculum guide in his living room when they ambush him.

“Dad? May I stay the night in the lab with Tony, please? I’d like to watch how he utilizes palladium for machine-based reactor operation. Bruce is staying, too, so there’ll be adult supervision.”

“Wait a minute – why do I not count as an adult?” Tony complains.

Brock watches as his eight year old rolls his eyes and flaps a hand at the engineer. “Come on, Tony. Even _I’m_ more of an adult than you are.”

Then, Max turns his gaze back to Brock. “Please, Dad, can I? I promise to be careful, and this would really help with my advanced sciences class at school.”

“Only since it’s not a school night,” Brock relents. “But tomorrow, mister, you’ve got chores to do. I can’t see the floor in your room right now and who knows what might be living in it. Deal?”

Max grins, pushes his floppy hair out of his eyes, and throws a fist pump into the air. Brock ends up with a lapful of squirming, cuddling child. “Deal! Awesome! Thanks, Dad!”

Max gives his father one last snuggle and shoots towards the elevator, chatting animatedly with Jarvis about neutrons or protons or something way over Brock’s head. Only when the doors close behind him does Brock let out the sigh he’s been holding. “Dad, he calls me lately. What happened to Daddy?”

Tony joins Brock on the couch, patting the frowning omega on the knee. “Your baby’s growing up. You’d better get used to it. Soon, he’ll be sneaking out of the Tower and ignoring you completely and falling in love with some pretty boy or girl.”

Brock glares at the engineer. “You’re a terrible person and a terrible friend,” he says. “My son’s going to be a virgin when he’s thirty. It’s not like I’ve forgotten how to use a gun.”

Tony laughs, and Brock continues, “It’s not funny! More and more often, I understand why parents get grey hair and wrinkles and ulcers.”

“You’ve got a few years to go on that, I think. Especially with the serum in your veins.”

“Not the point, Tony.”

“Yeah, I know.”

Brock covers his eyes with his hand and rubs them, then gestures to the book he’s reading. “I picked up Max’s PLP from Léman for next year, and I’m trying to figure out how the hell I can help him with his homework when I don’t understand half of the names of the classes he’s taking.”

Léman Manhattan Preparatory School had been a gift for Max from Tony and Pepper – registration and payment to one of the most prestigious schools in New York City to help satisfy his brilliant mind and insatiable curiosity. “And while I love that my son’s a genius, even reading over his personalized learning plans make me feel like a moron.”

“You’re not a moron,” Tony replies. “You’re a soldier and a strategist and a jock, but not a moron. Look, think about it this way – would Jane be able to help take out Doombots and shut down super cell tornadoes without Thor? Would Bruce be able to prevent building collapses and enhance machinery without the Hulk? We eggheads need muscle and we’re grateful to have muscle with common sense. Don’t ever downplay your part. Let me and Bruce handle science class and math, and you help Max with target practice and gym and not dying because he knows how to fight off an attacker.”

Brock doesn’t speak for a moment, but when he does, he’s choked up. “Thanks.”

Tony shrugs. “It’s true. In any case, I have better things to do than sit here holding your hand. I’ve got the future Chief Creative Officer of Stark Industries waiting for me and Bruce so he can play with Science™!”

Brock watches him leave, shaking his head. Leave it to Tony to make his motives sound selfish instead of admitting how much he adores spending time with Max. Alone again, he picks up the curriculum guide and tries to see which courses Max selected for the next semester, and how he can help his son choose the ones he wants most.

He continues reviewing the curriculum book, along with reading forms and pamphlets for Max’s after school clubs, fees, and details of his lab courses. It gives him a headache, and he sets it aside to go putter in the kitchen. After a while, his peace is interrupted by two bodies thumping and bumping out of the elevator.

“Honey, we’re home!”

Brock laughs, exits the kitchen, and greets his mate with a hug and a kiss. “I thought you weren’t back until Tuesday!”

“We’re just that good at our jobs,” James says, beaming at the other man. “What’re you doing? What smells good?”

Brock extracts himself from James’ grasp and presses himself against Steve. “I’m making lasagna,” he explains, giving his best friend a hug and a slap on the shoulder. Pulling away from Steve, he grins at both of them. “Tony’s keeping Max for the night, so I thought I’d get a few meals together for the freezer.”

James kisses him again, wanders towards the kitchen. “Will it be done soon?”

“In about an hour. There’re leftovers in the fridge from last night, if you two are hungry.”

“Actually, we have to debrief with Fury and Hill in about fifteen minutes,” Steve says. “We just wanted to let you know we’re back and get cleaned up before we talk.”

“Food’ll be done by the time you guys are done, then,” Brock replies. “Or, you can have your meeting in the dining room and you can all eat afterwards. I made two trays.”

“So one for me, and one for everyone else?” James asks.

“Well I wanted to make sure you’d have your strength up,” Brock teases, batting his eyes at his mate. “It would be a terrible shame for you to get tired easily.”

“You’d think you would both be over the honeymoon phase by now,” Steve grumbles at them, but smiles as he says it.

Brock likes the way Steve laughs at their mutual leering, no longer uncomfortable at the way they flirt with each other, or with him. He loves James more than anything, but he’s also got a soft spot for the single blond Alpha. “You enjoy every minute of our abuse,” he replies, and pokes Steve in the ribs. “Go call Fury and Hill and invite them. That way I can take good care of _both_ of you stubborn Alphas.”

Steve nods, heads back into the living room so he can speak to Jarvis. Brock watches him go, and tips his head to the side as strong arms encircle him from behind. “Thank you for taking care of him, too.”

Brock’s eyes close as he nuzzles his mate. “He’s a part of you, and a part of me, too. Of course I’m going to take care of him.”

“I don’t know how I got so lucky as to have the best mate on the planet,” James continues, reaching his metal arm to twist his fingers around Brock’s. “But I’m real glad you’re mine.”

With a final squeeze, they step apart. “So tell me what you’ve been doing while Stevie and I were gone?”

“Let’s see: cooking and cleaning, obviously. Your son has yet to clean his floor, so that’s his job tomorrow.”

“Why is he my son when he’s a mess, and your son the rest of the time?”

Brock glares at him and points toward the living room. “Tell me your gear bag’s not sitting on the couch right now after it’s been God-knows where.”

James shifts from foot-to-foot and coughs. “So what else has been keeping you busy?” he asks, trying to change the subject.

Brock lets him get away with the redirection, but grins anyway. “Workwise, I’ve been analyzing trucking patterns for potential Hydra operations with Hill and training with Nat and Clint. I’m still doing weight training though I don’t see why.”

It’s a sore spot. The older he gets, the more muscle mass he loses – even though he’s working out twice as hard as before. Bruce thinks his biology’s winning out over the serum in some aspects; that Brock might get a longer life and more strength than the average omega, but he won’t keep the bulk and muscle.

He’ll take longevity over his beefed-up shoulders any day.

“You’re gorgeous, whether you’re built like a weightlifter or built like a pencil,” James says, interrupting his thoughts. “Besides, look at me. I’m scrawny-looking compared to you and your muscles.”

“Because scrawny is definitely the first thing I think of when I see you,” Brock says, rolling his eyes. 

James nips his mate’s ear and Brock swats at him. “Anyway, it’s been pretty quiet around here, thank God. The only craziness is trying to help Max choose his PLP courses for next year.”

“Is he stacking the deck too high in math and science?”

This is the reason he loves James, Brock knows – not only for the amazing man he is, but because he listens and remembers every tiny detail about Max. “Exactly. He hasn’t made any choices in regards to English or foreign language. I know you’re teaching him Russian, but he also needs to be able to read and write his own language well.”

“We’ll sit down and talk with him tomorrow. Why’s he staying the night with Tony, anyway?”

“He, Bruce, and Max are doing a project in the lab.”

“Well, I’m glad Bruce is there to supervise,” Steve says, rejoining them in the kitchen. “Sorry it took me so long, but Hill was hard to reach. She was in that planning meeting with Pepper.”

James nods, and Brock wonders at the look he sees passing between the two of them. “Why do you two look so shifty all of a sudden?”

Steve gives him a wide-eyed look. “Shifty? Us? We’re innocent as lambs!”

“You’re a terrible liar, Steve,” James says. “It’s a Tony thing, don’t worry about it. Something regarding his security detail.”

Brock nods, but watches his mate closely; James scratches a hand across his stomach and heads to the dining room, grabbing Steve on the way. 

“They’re up to something,” the omega huffs, but doesn’t pursue it. 

When Hill and Fury finally arrive, the four Alphas camp out in the dining room. Brock, meanwhile, finishes the two trays of lasagna, presses garlic for fresh garlic bread, and digs through the fridge for the organic baby greens he ordered to use in a salad, throwing a handful of grape tomatoes, pumpkin seeds, and spinach into the mix. One of the best parts of semi-retiring from field work? Brock discovered he had exceptional talents other than mayhem and murder. Cooking became a quick love, along with raising Max. “Are you guys – and lady – ready to eat?” Brock calls into the other room.

“I’ve been ready to eat for an hour,” James replies. He appears in the doorway moments later. “Let me help you get plates inside, babe.”

“You sure you don’t want me to come in and serve you, kneel next to your chair while you eat?” Brock teases, knowing how much they _both_ hated the traditional Alpha/Omega stereotypes. 

He’s rewarded by the repulsed expression on James’ face. “No, thanks. I like you on your knees for other reasons.”

Brock throws his head back and cracks up. While he catches his breath, James grabs the salad and the individual salad bowls and heads back into the dining room. Brock dishes up the garlic bread and lasagna and joins him. He sets the first plate in front of James’ seat, respectful of his Alpha, and hands the other one to Hill. “Ladies first,” he says, and dodges the swat James aims at his ass. “Enjoy.”

Hill doesn’t hesitate to pick up her fork and slice off a corner of the thick, meaty dish. She chews and lets out a noise of satisfaction. “One day I just might steal you,” she says, straight-faced. “This is excellent.”

Brock grins, goes back to bring in plates for the others in the room, then grabs his own plate and joins them. They eat quietly for a bit, until Fury says, “Barton says you’ve been a great asset in finding European shipping channels.”

“I’ve had a lot of experience making it work from the other side,” Brock replies. “So I know what to look for.”

“Any chance you’d want to get into the field and take care of it more personally?”

Both James and Steve growl at Fury; Fury holds up a hand. “I told you both I’d ask him whether you liked it or not. I don’t know what you’re bitching about.”

“I’m sure James told you that I don’t want any part of field work anymore,” Brock says, shaking his head at Fury’s nerve. “Maybe if I didn’t have Max, I would consider it. But I like staying home with him and ensuring his happiness here. And James and I made a deal: one of us had to retire because Max always had to have one parent who was safe.”

“Never thought you’d actually be satisfied with that,” Fury says.

“Neither did I, but it’s the only part of my biology that I really seem to have taken to.”

“I took a shot,” Fury says. “It was worth it.”

They continue eating; Steve gets Hill and Fury to warm up to conversation about baseball, and James and he continue their conversation about Max’s school plans. The evening passes until nine, when Hill and Fury take their leave. Steve insists on doing the dishes while Brock and James sit in the living room on the couch. Brock asks, “So what’re you and Steve really up to?”

“Hmm?”

“That bullshit about Pepper and Hill in a meeting,” he clarifies. “Steve couldn’t look me in the eye afterwards.”

James shrugs, but doesn’t look him in the eye either. “Nothing. Just Tony stuff, I said.”

“You’d think you’d both be better liars, for ex-spies,” Brock says. “Seriously, what. What is it? Is there some Hydra threat I have to worry about? Did I accidently offend someone important? What?”

James throws his hands into the air. “Steve! Our nosy Omega’s making me crazy, come save me!”

Brock’s voice catches in his throat at his mate’s words, and he quietly asks, “Ours…?”

“Shit,” James says, wincing. “Steve! Hurry up before I put my foot further into my mouth!”

The blond Alpha hurries out of the kitchen. “What’s the matter?”

“Our Omega,” Brock blurts, and stares at the two of them. “What do you mean?”

Steve blushes; no other word for it. “Oh. Bucky, jeez.”

“Yeah, sorry.”

They stare at each other, and finally James says, “You know how traditionally an Alpha can take more than one Omega, if he or she wants?”

Brock nods, mouth completely dry. “You want another Omega?”

“No!” James says, looking horrified. “No, not at all! We… we were wondering if maybe you might want a second Alpha.”

He blinks at the pair of them, stupidly, unable to process his mate’s words. When the silence lingers, Steve says, “You know I’ve grown to love you as much as Bucky does. And you take as much care of me as you do him. This can’t be a shock to you.”

“B..but Alphas don’t share.”

“Isn’t that what we’ve been doing all along?” James asks. “We come home together to you. You touch us both, Brock. I can smell you on Steve as much as I can smell him on you, and I love it. I love having my family so closely bonded.”

“No one’s pressuring you,” Steve assures him. “We just wanted to put it out there, if you want.”

“Would you… bite me?”

“And you’d bite me, so we’d always be tied together. At least a little bit.”

“And you’d have to scent mark Max,” Brock says, warming to the idea in leaps and bounds. “Because you’ve been raising him right along with us.”

Steve looks flustered and honored and pleased all at once. “You’d trust me with your son?”

“Steve,” Brock says, helplessly. “When I first got here, I thought I’d have to leave, and I would’ve left him here with you and James because I thought he’d be better off. Of course I trust you with Max.”

Steve pounces on him, rubbing the two of them together and Brock moans into the affection. James wraps his arms around both of them, sandwiching Brock between the two Alphas in a safe cocoon. “You should say yes now,” James murmurs in Brock’s ear. “Let us both love you.”

“Yes,” Brock replies, drowning in the pheromones the two Alphas release. “Christ, yes. I never thought…”

“What didn’t you think?” Steve asks, when Brock turns his face to bury it in James’ chest. “Come on, Brock, tell us.”

“Never thought anyone would love me, let alone two good men,” Brock mumbles, embarrassed. “Fuck, someone shut me up, stupid hormones…”

Steve kisses him again, and Brock melts against him, opening his mouth to give Steve full access. Steve growls, kisses him harder, then leaves a trail of kisses over Brock’s jawline. Brock mewls at the sensation of Steve’s mouth against his throat. “Please,” he begs. “Mark me?”

James licks a stripe up his neck on the other side of Steve’s kisses, and soon Brock feels both of them leaving love bites over his skin. The Omega can barely breathe, cock heavy and full in his pants. “Need skin,” he finally pants. “Bedroom? Bed?”

James scoops him up and Steve presses one more kiss to his lips, and then the trio’s moving, down the hall and to the lush king-sized bed in the master bedroom. When James lays him to rest on the bed, he draws his mate forward and starts pulling at his shirt. “Skin!” he demands.

James chuckles, whips his shirt off. “Better?”

Brock nods, his biology making him pre-verbal. Instead of speaking, he makes grabby hands at Steve. Steve just grins. “Buck, I think our sweet Omega wants us naked.”

“Well, never let it be said that we don’t oblige.”

Brock’s not really sure how they get naked, or how he himself gets naked, but as soon as there’s lots of skin on his he doesn’t care. James is busy nibbling the mating bite on his neck, and Steve’s licking his nipples, and Brock’s a whining, whimpering ball of want. “That,” he says, when Steve’s mouth moves further south. “Oh!”

Steve’s lapping his cock, fingers questing into the wetness of his hole; meanwhile, James is biting a deep, deep mark into the mating gland on his neck. “Bruce told us some of the science of dual mating,” James says, between nips. “Told me how the mate bite’s gotta be the deepest, most aggressive bite, but that if someone else bites over it, they can tie to you too.”

“Want that,” Brock begs. “Yes.”

“I know, sweetheart. And we’re going to give it to you.”

With that, James bites hard enough to draw blood. Brock cries out, but the pain’s a short, bittersweet burst; not like when James had been the Soldier and hadn’t cared. The pain magnifies the pleasure already coursing through his body and, startled by how good it feels, Brock spills onto Steve’s tongue.

“Mmm,” Steve rumbles, sending shockwaves along Brock’s skin, “Like honey.”

James doesn’t pause with his vampire impression until Brock whimpers and paws at him. “Too much,” he pleads. “Sensitive.”

Both Alphas watch him, hold him and cuddle him until he stops shaking. “You okay?”

Brock nods. He reaches out; but for the first time, it’s for Steve and not his mate. “Bite me?”

The blond smiles a beautiful, painful smile. “I’ve wanted you for so long,” he says, and kisses Brock sweetly. “I hated you so much, and then I loved you twice as hard.”

“Me too,” Brock responds. “You’ve been a part of me from the beginning.”

Steve leans over him, puts his mouth over the still-bleeding bite mark. “You ready?”

“Yes.”

And the Alpha bites.

Immediately, a secondary bond – not as strong as the mating bond, but close – flares to life between them, and Brock arches against Steve. He reaches for James’ hand, the metal fingers cool against his feverish skin, and James squeezes gently. “Did it work?”

“God,” Steve says, peppering kisses on Brock’s face. “Yeah. Wow.”

James settles onto Steve’s lap, kisses the other Alpha, and Brock watches joyfully as the two of them hold each other. 

“It’s beautiful,” the Omega says, grinning. “I’ve got both of you, now.”

“And we’ve got you.”

The three of them cling together for a minute, and then spend the rest of the night exploring their newfound family ties.

&&&&&

When Brock wakes the next morning, he realizes that he’s smothering half under Steve’s bulky frame. He gives the blond a gentle nudge, urging him to roll over, and then crawls across James’ body to get out of the bed.

“Where’re you goin’?” James mumbles, grabbing onto him and preventing his progress.

“Bathroom. And Max could be home at any minute, so I wanted to wake up. But mostly I don’t want to pee on you.” 

“Might be a little extreme for scent marking,” James agrees, and releases him. “Hmm… feeling kinda possessive of you this morning, sweetheart.”

“Me, too,” Steve yawns from the other side of the bed.

“Well, how about we stay on our floor all day, watch movies with Max and cuddle? We’ve got plenty of food and neither of you has an op to worry about. Think about it while I hit the head.”

Brock shuffles into the bathroom and pees, grinning at his reflection in the mirror afterwards. The bite – with two distinct sets of teeth marks – glows on his skin. He washes his hands and returns to the bedroom, pulling on a pair of pajama pants and a sleeveless tee. “So? Breakfast?”

“Mmm…” Steve says, lazing in the bed. Brock chuckles at how Steve and James are completely wrapped up in each other. “Don’t want to move.”

“Okay, but I’ll miss you both,” he replies, and with that, he heads into the kitchen to get the coffee going.

Ten minutes pass and as he’s beating eggs in a bowl, two sleepy-eyed faces join him. “You look like the cat that got the cream, sweetheart,” James teases, pulling his mate close for a kiss. “Happy?”

“More than I can say. And I think I have enough energy today to power half of Manhattan,” Brock admits. “That was amazing. I can’t tell you how much I love having both of you as mine.”

“It’s not a one-time deal, you know,” Steve says. “We were thinking about suggesting moving to one of the other floors, with three bedrooms instead of two? That way, we’d have more space, and the four of us could live together.”

“I’d really love that,” Brock says. “I’m not partial to the place… just the people.”

“Sweet talker.”

Brock laughs. “You know it. It’s kinda funny, though.”

“What is?”

“This,” Brock says, gesturing between the three of them. “I had no idea this is what you were going to suggest last night.”

“Yeah? And what did you think we were up to?”

“I thought it had something to do with the surprise party Max and Pepper are planning for when I turn forty next week.”

And hah! Busted. Both Alphas go wide eyed and stiff. “Surprise party? What surprise party?” James asks, playing dumb.

“The party that Max’s got a notebook for on his desk that says, ‘Dad’s 40th: Top Secret!’ with a list of names, decorations, food… _that_ surprise party.”

James groans, thumps his head down onto the counter. “God, our kid,” he groans. “Definitely not cut out for the spy game.”

Steve’s shaking his head as Brock shrugs. “Not that either of you are blameless in giving it away. I mean, my God, could you have been more obvious last night, with that ‘meeting’ between Hill and Pepper? Terrible spies, both of you.”

“I’m not technically a spy,” Steve protests, but it’s too late. Brock’s too busy laughing at them to care. 

“Don’t worry, I’ll pretend to be plenty surprised. I was kind of shocked that Pepper and Hill are both helping, but I’d bet that had something to do with how convincing our son is…”

“And the fact that both of us have been gone lately,” James says. “But for the next two weeks, neither of us are going anywhere. So you’re stuck with us.”

“Well, then I guess my birthday wish has already come true,” Brock replies. “Because you two, and Max? That’s all I could ever ask for, or want.”

As they sit down to eat, the elevator doors chime, announcing Max’s return home. Brock cuddles his child, serves him a plate, and watches as Max takes in the new smell dynamic of the three men. “Finally!” he says. “Tony so owes me money! I knew Pop and Steve would take Bruce’s advice.”

The three adults stare flabbergasted at the boy. “Uh. What exactly did Tony tell you, buddy?” Brock asks, somewhat ready to murder Tony. “Word for word, please?”

“That if Steve bit you after Pop did, the three of you would bond and Uncle Steve would become a permanent part of our family,” Max replies, blinking. “Why? What else would he say?”

“Who knows what Tony would say,” James says, and sighs in relief. At least the engineer used discretion, for once. “But we’re going to move to a different floor soon, Max, so that all of us can live together. Would you like that?”

Max beams. “You mean Steve will be around all the time? That would be so cool! Yes! Let’s do that! Isn’t that the best?”

“Best present ever,” Brock agrees, and ruffles his son’s hair.

**Author's Note:**

> So I don't know if there's a part 5 or not. I'm sort-of drabbling something, but this may be the end. Thank you for reading!!!


End file.
